Streptococcus Pneumoniae (Pneumococcus)

Epidemiology

Risk Factors

Human Immunodeficiency Virus (HIV) (see Human Immunodeficiency Virus, [[Human Immunodeficiency Virus]])
Influenza Virus (see Influenza Virus, [[Influenza Virus]])
- Mechanisms:
  - Influenza virus damages tracheobronchial epithelium with loss of cilia and decrease in cell size
  - Influenza virus also enhances the attachment of Streptococcus Pneumoniae to nasopharyngeal epithelial cells, enhancing colonization [MEDLINE]
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Microbiology

Member of Streptococcus Genus (see Streptococcus, [[Streptococcus]])

Diagnosis

Sputum Culture (see Sputum Culture, [[Sputum Culture]])

Appearance: lancet-shaped diplococci
Penicillin resistance (35% of isolates have some level of PCN-resistance/60% of isloates have high-level resistance): mediated by altered penicillin-binding proteins (PBP’s)
- Resistance to PCN’s usually is associated with resistance to erythro, tetracyclines, chloramphenicol, and bactrim
- Most strains in US are still sensitive to clinda
Macrolide resistance: 25% of strains are macrolide-resistant
Bactrim resistance: 30% of strains are bactrim-resistant
Multidrug resistance: 22.5% of strains are multidrug-resistant
Fluoroquinolone-resistance: only 1% of strains in US are fluoroquinolone-resistant (resistance rate is higher in US subpoulations of elderly who have previously received a fluoroquinolone and in other countries)

CXR/Chest CT Pattern (see xxxx, [[xxxx]])x

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Clinical Manifestations

Hematologic Manifestations

Hemolytic Anemia (see Hemolytic Anemia, [[Hemolytic Anemia]])

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Hemolytic-Uremic Syndrome (see Thrombotic Microangiopathy, [[Thrombotic Microangiopathy]])

Epidemiology
- Age: usually <2 y/o
- Usually occurs in association with pneumococcal sepsis, pneumonia with empyema, or meningitis with subdural empyema
Physiology
- Pneumococcal neuraminidase has been identified in the plasma: it causes de-sialation of the glycocalyx of cells, exposing the Thomsen-Friedenreich (T-) antigen (which ss normally covered by sialic acid)
- T-anti-T interaction on RBC’s/platelets/endothelium was thought to explain the pathogenesis, but the role of the anti-T cold antibody in vivo is questionable
Diagnosis
- Positive Coombs Test: in contrast to other types of HUS
  - Exposed T-antigen on RBC’s is detected using the lectin Hypogeae
  - An IgM cold antibody occurring naturally in human serum causes in vitro polyagglutination
Clinical
- Marked Microangiopathic Hemolytic Anemia
Prognosis
- Acute Mortality: 25%
- Relapse of HUS has not been reported

Otolaryngologic Manifestations

Acute Otitis Media (see Acute Otitis Media, [[Acute Otitis Media]]): most important bacterial etiology of acute otitis media in adults
Acute Rhinosinusitis (see Acute Rhinosinusitis, [[Acute Rhinosinusitis]]): accounts for 41% of acute rhinosinusitis cases
Deep Neck Infection (see Deep Neck Infection, [[Deep Neck Infection]]): common etiology

Pulmonary Manifestations

Necrotizing Pneumonia (see Necrotizing Pneumonia and Pulmonary Gangrene, [[Necrotizing Pneumonia and Pulmonary Gangrene]])

Pneumonia (see Pneumonia, [[Pneumonia]])

Epidemiology
- Most common etiology of community-acquired pneumonia (CAP)
Risk Factors
- Overcrowding/Poor Ventilation: institutional settings
- Asplenia (see Asplenia, [[Asplenia]])
- Human Immunodeficiency Virus (HIV) (see Human Immunodeficiency Virus, [[Human Immunodeficiency Virus]])
- Influenza Virus (see Influenza Virus, [[Influenza Virus]])
- Respiratory Syncytial Virus (RSV) (se Respiratory Syncytial Virus, [[Respiratory Syncytial Virus]])
  - Study Citing Association Between RSV Infection and Pneumococcal Pneumonia in Infants (2014) [MEDLINE]: interestingly, the study also cited a decrease in RSV-coded hospitalizations after introduction of the seven-valent pneumococcal conjugate vaccine
Clinical
- Dyspnea
- Cough with Sputum Production
- Upper Respiratory Symptoms

Acute Respiratory Distress Syndrome (ARDS) (see Acute Respiratory Distress Syndrome, [[Acute Respiratory Distress Syndrome]])

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Sepsis (see Sepsis, [[Sepsis]])

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Prevention-Pneumoccocal Vaccination

Pneumococcal Conjugate Vaccine 13 (PCV13) (Prevnar 13)

General Information

Vaccine Contains Capsular Polysaccharides from 13 Pneumococcal Serotypes Covalently Linked to a Non-Toxic Protein Which Resembles Diphtheria Toxin: linking allows capsular antigens to be immunogenic to children <2 y/o
- PCV13 Stimulates Mucosal Antibody: functions to suppress nasal carriage of the covered pneumococcal serotypes -> this prevents spread of these serotypes from small childre (the usual reservoir for pneumococcus) to unvaccinated children and adults (so called, “herd effect”)
General Indications
- Children <2 y/o
- Selected Adults: see below
  - 2012: US Advisory Committee on Immunization Practices (ACIP) Recommended PCV13 for Selected High-Risk Adult Populations
  - 2014: ACIP Recommended PCV13 for All Adults ≥65 y/o and Patients >2 y/o with Conditions Which Increase Risk for Pneumococcal Infection

Adult Groups Recommended for Vaccination with PCV13

Immunocompetent
- Cerebrospinal Fluid Leak
- Cochlear Implant
Immunocompromised
- Asplenia (see Asplenia, [[Asplenia]])
  - Sickle Cell Disease/Other Hemoglobinopathy
  - Congenital/Acquired Asplenia
- Chronic Kidney Disease (CKD) (see Chronic Kidney Disease, [[Chronic Kidney Disease]])
- Congenital/Acquired Immunodeficiency
  - B-Cell/T-Cell Deficiency
  - Complement Deficiency (Especially C1, C2, C3, and C4)
  - Phagocytic Disorders (Excluding Chronic Granulomatous Disease)
- Hodgkin’s Disease (see Hodgkin’s Disease, [[Hodgkins Disease]])
- Human Immunodeficiency Virus (HIV) (see Human Immunodeficiency Virus, [[Human Immunodeficiency Virus]])
- Iatrogenic Immunosuppression
  - Corticosteroids (see Corticosteroids, [[Corticosteroids]])
  - Immunosuppressants
  - Radiation Therapy (see Radiation Therapy, [[Radiation Therapy]])
- Leukemia
- Lymphoma (see Lymphoma, [[Lymphoma]])
- Malignancy
- Multiple Myeloma (see Multiple Myeloma, [[Multiple Myeloma]])
- Nephrotic Syndrome (see Nephrotic Syndrome, [[Nephrotic Syndrome]])
- Solid Organ Transplant

23-Valent Pneumococcal Polysaccharide Vaccine (PPSV23) (Pneumovax 23)

General Information

Vaccine Contains Capsular Polysaccharides from 23 Pneumococcal Serotypes: these serotypes account for 60% of human pneumococcal infections
General Indications
- Children ≥2 y/o: polysaccharides are poorly immunogenic in children <2 y/o
- Selected Adults: see below
Duration of Antibody Response: 10 yrs

Adult Groups Recommended for Vaccination with PPSV23

Immunocompetent
- Age ≥65 y/o
- Alcohol Abuse (see Ethanol, [[Ethanol]])
- Cerebrospinal Fluid Leak
- Chronic Liver Disease/Cirrhosis (see End-Stage Liver Disease, [[End-Stage Liver Disease]])
- Chronic Lung Disease
  - Asthma (see Asthma, [[Asthma]])
  - Chronic Obstructive Pulmonary Disease (COPD) (see Chronic Obstructive Pulmonary Disease, [[Chronic Obstructive Pulmonary Disease]])
- Cochlear Implant
- Congestive Heart Failure (CHF)/Cardiomyopathy (see Congestive Heart Failure, [[Congestive Heart Failure]])
- Diabetes Mellitus (DM) (see Diabetes Mellitus, [[Diabetes Mellitus]])
- Tobacco Abuse (see Tobacco, [[Tobacco]])
Immunocompromised
- Asplenia (see Asplenia, [[Asplenia]])
  - Sickle Cell Disease/Other Hemoglobinopathy
  - Congenital/Acquired Asplenia
- Chronic Kidney Disease (CKD) (see Chronic Kidney Disease, [[Chronic Kidney Disease]])
- Congenital/Acquired Immunodeficiency
  - B-Cell/T-Cell Deficiency
  - Complement Deficiency (Especially C1, C2, C3, and C4)
  - Phagocytic Disorders (Excluding Chronic Granulomatous Disease)
- Hodgkin’s Disease (see Hodgkin’s Disease, [[Hodgkins Disease]])
- Human Immunodeficiency Virus (HIV) (see Human Immunodeficiency Virus, [[Human Immunodeficiency Virus]])
- Iatrogenic Immunosuppression
  - Corticosteroids (see Corticosteroids, [[Corticosteroids]])
  - Immunosuppressants
  - Radiation Therapy (see Radiation Therapy, [[Radiation Therapy]])
- Leukemia
- Lymphoma (see Lymphoma, [[Lymphoma]])
- Malignancy
- Multiple Myeloma (see Multiple Myeloma, [[Multiple Myeloma]])
- Nephrotic Syndrome (see Nephrotic Syndrome, [[Nephrotic Syndrome]])
- Solid Organ Transplant

Intervals and Sequence of Pneumococcal Vaccinations (MMWR, 2015) [MEDLINE]

Asplenia/CKD/Cochlear Implant/CSF Leak/Immunocompromised at Any Age and Have Not Received Either PCV13 or PPSV23
- Now: PCV13
- 8 Weeks Later: PPSV23
Asplenia/CKD/Cochlear Implant/CSF Leak/Immunocompromised at Any Age and Have Previously Received PPSV23
- 1 Year After PPSV23 Dose: PCV13
Age ≥65 y/o without Above Conditions
- 1 Year After PCV13 (and at Least 5 Years After Last PPSV23): PPSV23
Age <65 y/o and Requiring Revaccination (i.e. Immunocompromised)
- PPSV23 Should Be Given at Least 8 Weeks After PCV13 and at Least 5 Years After Last PPSV23 Dose

Revaccination

Immunocompetent
- Age ≥65 y/o: all adults ≥65 y/o should be revaccinated, even if they were vaccinated before age 65 (with a minimum of 5 years between PPSV23 doses)
Immunocompromised: patients in these groups <65 y/o should be revaccinated one time (with a minimum of 5 years between PPSV23 doses) and again after age 65 (with a minimum of 5 years between PPSV23 doses)
- Asplenia (see Asplenia, [[Asplenia]])
  - Sickle Cell Disease/Other Hemoglobinopathy
  - Congenital/Acquired Asplenia
- Chronic Kidney Disease (CKD) (see Chronic Kidney Disease, [[Chronic Kidney Disease]])
- Congenital/Acquired Immunodeficiency
  - B-Cell/T-Cell Deficiency
  - Complement Deficiency (Especially C1, C2, C3, and C4)
  - Phagocytic Disorders (Excluding Chronic Granulomatous Disease)
- Hodgkin’s Disease (see Hodgkin’s Disease, [[Hodgkins Disease]])
- Human Immunodeficiency Virus (HIV) (see Human Immunodeficiency Virus, [[Human Immunodeficiency Virus]])
- Iatrogenic Immunosuppression
  - Corticosteroids (see Corticosteroids, [[Corticosteroids]])
  - Immunosuppressants
  - Radiation Therapy (see Radiation Therapy, [[Radiation Therapy]])
- Leukemia
- Lymphoma (see Lymphoma, [[Lymphoma]])
- Malignancy
- Multiple Myeloma (see Multiple Myeloma, [[Multiple Myeloma]])
- Nephrotic Syndrome (see Nephrotic Syndrome, [[Nephrotic Syndrome]])
- Solid Organ Transplant

Treatment

High-Level Resistance (MIC90>2 µg/mL): preferred treatment for high-level resistance is vanco (ceftriax, imipenem are ok but ceftaz is poor)
Multidrug-Resistant Pneumococci: vanco or newer fluoroquinolones (levo/gati/moxi) or linezolid or synercid
Second Generation Cephalosporin

Community-Acquired Pneumonia (CAP)

Ceftaroline (Teflaro, Zinfloro) (see Ceftaroline, [[Ceftaroline]])

References

General

High nasopharyngeal pneumococcal density, increased by viral coinfection, is associated with invasive pneumococcal pneumonia. J Infect Dis. 2014 Nov 15;210(10):1649-57. doi: 10.1093/infdis/jiu326. Epub 2014 Jun 6 [MEDLINE]
Association between Respiratory Syncytial Virus Activity and Pneumococcal Disease in Infants: A Time Series Analysis of US Hospitalization Data. PLoS Med. 2015 Jan 6;12(1):e1001776. doi: 10.1371/journal.pmed.1001776. eCollection 2015 [MEDLINE]

Vaccination

Pneumococcal vaccination of older adults: conjugate or polysaccharide? Hum Vaccin Immunother. 2013 Jun;9(6):1382-4. doi: 10.4161/hv.24692. Epub 2013 May 31 [MEDLINE]
Use of 13-Valent Pneumococcal Conjugate Vaccine and 23-Valent Pneumococcal Polysaccharide Vaccine Among Adults Aged ≥65 Years: Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR 2013; 63: 822-825 [MEDLINE]
Advisory committee on immunization practices recommended immunization schedule for adults aged 19 years or older–United States, 2015. MMWR Morb Mortal Wkly Rep. 2015 Feb 6;64(4):91-2 [MEDLINE]
Intervals Between PCV13 and PPSV23 Vaccines: Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Morb Mortal Wkly Rep. 2015 Sep 4;64(34):944-7. doi: 10.15585/mmwr.mm6434a4 [MEDLINE]